require "kconv"

class GraFile
  GRA_PREFIX = "%Ngraph GRAF"
  SEPARATOR  = Regexp::new(/[,\t ]/)
  REG_HEX    = Regexp::new(/\\x[0-9a-fA-F][0-9a-fA-F]/)
  NGP_FILE   = Regexp::new(/.*\.ngp$/)
  NGP_WIDTH  = Regexp::new(/gra::paper_width=[0-9]+/)
  NGP_HEIGHT = Regexp::new(/gra::paper_height=[0-9]+/)

  def GraFile.foreach(f, ignore_path = "")
    f =  "|ngraph -i ngp2 - #{ignore_path} - #{f}" if(f =~ NGP_FILE)
    file = open(f, "r")
    if(file.gets.chomp != GRA_PREFIX) then return nil end

    size = nil
    file.each do |l|
      l.chomp!
      cmd = l[0]
      case cmd
      when ?I, ?E, ?V, ?A, ?G, ?M, ?N, ?L, ?T, ?C, ?B, ?P, ?R, ?D, ?H
	item = l.split(SEPARATOR).collect!{|i| i.to_i}
	if(item.size != item[1] + 2) then return nil end
	item.delete_at(1)
	item[0] = cmd
	if(cmd == ?I)
	  size = [item[3], item[4]]
	end

      when ?%, ?F, ?K
	item = [cmd, l[1..-1]]

      when ?S
	s = " "
	item = [cmd, l[1..-1]]
      else
	return nil
      end
      yield(item)
    end
    file.close
    size
  end

  def GraFile.size(f)
    size = nil
    file = File::new(f, "r")
    if(f =~ NGP_FILE)
      width = nil
      height = nil
      file.each{|l|
	if(l =~ NGP_WIDTH)
	  width = l.split("=")[1].to_f
	elsif(l =~ NGP_HEIGHT)
	  height = l.split("=")[1].to_f
	end
      }
      size = if(width && height) then [width, height] else [21000, 29700] end
    else
      if(file.gets.chomp! == GRA_PREFIX)
	file.each{|l|
	  l.chomp!
	  if(l[0] == ?I)
	    item = l.split(SEPARATOR).collect!{|i| i.to_i}
	    size = [item[4], item[5]]
	    break
	  end
	}
      end
    end
    file.close
    size
  end
end

class Gra2Ngp
  NGRAPH_INI = "/Ngraph.ini"
  NGRAPH_PATH = [ENV["NGRAPHHOME"], ENV["HOME"], "/usr/local/lib/Ngraph"]

  JOIN_STYLE = ["miter", "round", "bevel"]
  FILL_RULE  = ["empty", "even_odd_rule", "winding_rule"]
  ARC_MODE   = [true, true, false]

  def initialize
    @size = [0, 0]
    @margin = [0, 0]

    @font = ["Helv", "Goth", 1800, 0, 0]
    @color = [0, 0, 0]
    @org_ptr = [0, 0]
    @cur_ptr = [0, 0]
    @line_array = []
    @line_style = [40, JOIN_STYLE[0], ""]
    @zoom = 1000
    @fontmap = nil

    read_fontmap
  end

  def draw(i)
    if(i[0] != ?T && !@line_array.empty?)
      draw_lines(@line_array)
      @line_array.clear
    end

    case i[0]
    when ?I
      @margin[0..1] = [i[1], i[2]]
      @size[0..1] = [i[3], i[4]]
      @org_ptr[0..1] = @margin
      @zoom = i[5]
      @line_array.clear
      new_gra

    when ?V
      @org_ptr[0..1] = [i[1], i[2]]

    when ?A
      width = [1, i[2]].max
      if i[1] == 0
	style = ""
      else
	style = i[6..-1].join(" ")
      end
      join = JOIN_STYLE[i[4]]
      @line_style = [width, join, i[5], style]

    when ?G
      @color = i[1..3]

    when ?M
      @cur_ptr[0..1] = [i[1], i[2]]

    when ?N
      @cur_ptr[0..1] = [@cur_ptr[0]+i[1], @cur_ptr[1]+i[2]]

    when ?L
      draw_line(@org_ptr[0]+i[1], @org_ptr[1]+i[2], @org_ptr[0]+i[3], @org_ptr[1]+i[4])

    when ?T
      if(@line_array.empty?)
	@line_array.push(@cur_ptr[0]+@org_ptr[0])
	@line_array.push(@cur_ptr[1]+@org_ptr[1])
      end
      @line_array.push(@org_ptr[0]+i[1])
      @line_array.push(@org_ptr[1]+i[2])
      @cur_ptr[0..1] = [i[1], i[2]]

    when ?C
      x = @org_ptr[0]+i[1]
      y = @org_ptr[1]+i[2]
      draw_arc(i[7] != 0, ARC_MODE[i[7]], x, y, i[3], i[4], i[5], i[6])

    when ?B
      draw_rectangle(i[5] != 0, @org_ptr[0]+i[1], @org_ptr[1]+i[2], @org_ptr[0]+i[3], @org_ptr[1]+i[4])

    when ?P
      draw_point(@org_ptr[0]+i[1], @org_ptr[1]+i[2])

    when ?R
      draw_lines(add_offset(i[2..-1], @org_ptr))

    when ?D
      draw_polygon(FILL_RULE[i[2]], add_offset(i[3..-1], @org_ptr))

    when ?H
      @font[2..3] = [i[1], i[2], i[3]]

    when ?F
      if(@fontmap[i[1]] == 1)
	@font[1] = i[1]
      else
	@font[0] = i[1]
      end

    when ?S
      draw_str(i[1].tosjis.gsub(/[@^_%']/,'\\\\\0')) #'

    when ?K
      draw_str(i[1].tosjis)

    when ?%
	print "# #{i[1]}\n"

    end
  end

  def draw_line(x1, y1, x2, y2)
    print <<-EOF
      new line
      line::R=#{@color[0]}
      line::G=#{@color[1]}
      line::B=#{@color[2]}
      line::points='#{x1} #{y1} #{x2} #{y2}'
      line::width=#{@line_style[0]}
      line::join=#{@line_style[1]}
      line::miter_limit=#{@line_style[2]}
      line::style='#{@line_style[3]}'

      EOF
  end

  def draw_rectangle(fill, x1, y1, x2, y2)
    print <<-EOF
      new rectangle
      rectangle::R=#{@color[0]}
      rectangle::G=#{@color[1]}
      rectangle::B=#{@color[2]}
      rectangle::x1='#{x1}'
      rectangle::y1='#{y1}'
      rectangle::x2='#{x2}'
      rectangle::y2='#{y2}'
      rectangle::fill='#{fill}'
      rectangle::width=#{@line_style[0]}
      rectangle::style='#{@line_style[3]}'

      EOF
  end

  def draw_lines(ptr)
    print <<-EOF
      new line
      line::R=#{@color[0]}
      line::G=#{@color[1]}
      line::B=#{@color[2]}
      line::width=#{@line_style[0]}
      line::join=#{@line_style[1]}
      line::miter_limit=#{@line_style[2]}
      line::style='#{@line_style[3]}'
      line::points='#{ptr.join(" ")}'

      EOF
  end

  def draw_polygon(fill, ptr)
    print <<-EOF
      new polygon
      polygon::R=#{@color[0]}
      polygon::G=#{@color[1]}
      polygon::B=#{@color[2]}
      polygon::fill=#{fill}
      polygon::width=#{@line_style[0]}
      polygon::join=#{@line_style[1]}
      polygon::miter_limit=#{@line_style[2]}
      polygon::style='#{@line_style[3]}'
      polygon::points='#{ptr.join(" ")}'

    EOF
  end

  def draw_str(str)
    print <<-EOF
      new text
      text::text='#{str}'
      text::x=#{@cur_ptr[0]+@org_ptr[0]}
      text::y=#{@cur_ptr[1]+@org_ptr[1]}
      text::font=#{@font[0]}
      text::jfont=#{@font[1]}
      text::pt=#{@font[2]}
      text::space=#{@font[3]}
      text::direction=#{@font[4]}
      text::R=#{@color[0]}
      text::G=#{@color[1]}
      text::B=#{@color[2]}

    EOF
  end

  def draw_arc(fill, pieslice, x, y, rx, ry, start, stop)
    print <<-EOF
      new arc
      arc::R=#{@color[0]}
      arc::G=#{@color[1]}
      arc::B=#{@color[2]}
      arc::fill=#{fill}
      arc::pieslice=#{pieslice}
      arc::x=#{x}
      arc::y=#{y}
      arc::rx=#{rx}
      arc::ry=#{ry}
      arc::width=#{@line_style[0]}
      arc::style='#{@line_style[3]}'

    EOF
  end

  def new_gra
    print <<-EOF
      new gra name:viewer
      gra::left_margin=#{@margin[0]}
      gra::top_margin=#{@margin[1]}
      gra::zoom=#{@zoom}
      gra::paper_width=#{@size[0]}
      gra::paper_height=#{@size[1]}

    EOF
  end

  def add_offset(a, o)
    ptr = []
    (0...a.size/2).each do |i|
      ptr.push(a[i*2]   + o[0])
      ptr.push(a[i*2+1] + o[1])
    end
    ptr
  end

  def read_fontmap
    file = nil
    if NGRAPH_PATH.each { |path|
	if(path != nil && test(?r, path + NGRAPH_INI))
	  file = path + NGRAPH_INI
	  break
	end
      } then
      printf $stderr, "Can't find %s\n\n", NGRAPH_INI
      exit
    end
    fmap = {}
    section = nil
    IO::foreach(file) do |l|
      l.chomp!
      if(l =~ /^\[.+\]$/)
	section = l;
	next
      end

      if(section == '[x11menu]')
	m = l.split('=')
	if(m[0] == 'font_map')
	  f = m[1].split(',')
	  fmap[f[0]] = f[2].to_i
	end
      end
    end
    @fontmap = fmap
  end
end

ngp = Gra2Ngp.new
GraFile.foreach(ARGV[0]){|l|
  ngp.draw(l)
}